Aircraft gunnery practice requires an inexpensive form of ammunition which accurately simulates the ballistic characteristics of the normal load used in hostile action. The need for target practice ammunition usually far exceeds the amount maintained for wartime reserve. Therefore, any economies that can be accomplished in the cost of a target practice round would result in substantial savings.
The conventional target practice projectile which is shot from a moving airplane has shown a tendency to ricochet or broach upon the ground during strafing runs, thereby endangering other aircraft and personnel in the vicinity. This also severely limits the locations at which this activity can be performed.
It is, therefore, the object of this invention to provide an economical practice round which will break up on ground impact, minimize ricochets and limit high velocity fragments after impact.
A solid plastic projectile which could be injection molded in a one-shot step was investigated. However, it proved extremely difficult to obtain the desired ballistic characteristics without the use of high density plastics with sophisticated fillers, thereby defeating the advantages of using plastic. Similar problems arose with respect to flexural strength requirements. It is therefore an object of this invention to provide a combination steel and plastic projectile which can be assembled with conventional injection molding techniques and utilize ordinary filled plastic material.